Board Thread:Pokémon Help/@comment-32195150-20170610173446/@comment-27535813-20170612101920

There are a lot of possible counters that are effective(and are/maybe meta in the current PBB) against Manaphy.

Such as: Shaymin-Sky, Unaware Clefable and Gengar. (all of these Pokemon can revenge kill/annoy/chase out)

Anything that resists Manaphy, tanks special attacks or outspeeds Manaphy(since Manaphy only has 100 base speed) goes well with your team.

Magneton only has 70 base speed so that won't outspeed Manaphy any time soon lol. (unless it holds something like Choice Scarf which isn't around yet)